6c690ee103
The kernel has several code paths that read CR3. Most of them assume that CR3 contains the PGD's physical address, whereas some of them awkwardly use PHYSICAL_PAGE_MASK to mask off low bits. Add explicit mask macros for CR3 and convert all of the CR3 readers. This will keep them from breaking when PCID is enabled. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
48 lines
1.5 KiB
C
48 lines
1.5 KiB
C
#ifndef _ASM_X86_PROCESSOR_FLAGS_H
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#define _ASM_X86_PROCESSOR_FLAGS_H
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#include <uapi/asm/processor-flags.h>
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#ifdef CONFIG_VM86
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#define X86_VM_MASK X86_EFLAGS_VM
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#else
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#define X86_VM_MASK 0 /* No VM86 support */
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#endif
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/*
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* CR3's layout varies depending on several things.
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*
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* If CR4.PCIDE is set (64-bit only), then CR3[11:0] is the address space ID.
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* If PAE is enabled, then CR3[11:5] is part of the PDPT address
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* (i.e. it's 32-byte aligned, not page-aligned) and CR3[4:0] is ignored.
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* Otherwise (non-PAE, non-PCID), CR3[3] is PWT, CR3[4] is PCD, and
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* CR3[2:0] and CR3[11:5] are ignored.
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*
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* In all cases, Linux puts zeros in the low ignored bits and in PWT and PCD.
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*
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* CR3[63] is always read as zero. If CR4.PCIDE is set, then CR3[63] may be
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* written as 1 to prevent the write to CR3 from flushing the TLB.
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*
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* On systems with SME, one bit (in a variable position!) is stolen to indicate
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* that the top-level paging structure is encrypted.
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*
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* All of the remaining bits indicate the physical address of the top-level
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* paging structure.
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*
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* CR3_ADDR_MASK is the mask used by read_cr3_pa().
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*/
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#ifdef CONFIG_X86_64
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/* Mask off the address space ID bits. */
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#define CR3_ADDR_MASK 0x7FFFFFFFFFFFF000ull
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#define CR3_PCID_MASK 0xFFFull
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#else
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/*
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* CR3_ADDR_MASK needs at least bits 31:5 set on PAE systems, and we save
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* a tiny bit of code size by setting all the bits.
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*/
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#define CR3_ADDR_MASK 0xFFFFFFFFull
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#define CR3_PCID_MASK 0ull
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#endif
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#endif /* _ASM_X86_PROCESSOR_FLAGS_H */
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